BUENOS AIRES, Argentina (CNN) -- Two former generals accused of murdering a senator during Argentina's military dictatorship were sentenced to life in prison Thursday.

Antonio Bussi and Luciano Menendez were found guilty of kidnapping and murdering Sen. Guillermo Vargas Aignasse, who was last seen in public March 24, 1976, the day of a military coup.

The men, both in their 80s, showed no remorse during the trial, which took place in the interior city of San Miguel de Tucuman. They argued that they were simply defending Argentina from a guerrilla movement.

"I consider myself politically persecuted by the defeats of yesterday in the just and necessary war," Bussi said.

He insisted that Vargas Aignasse was kidnapped and assassinated by the guerrllia organization Monteros, which he had denounced.

"It was war, the most total of all wars, the revolutionary war," said Menendez, who was Bussi's immediate boss. "They weren't just trying to take a piece of territory from us, it was the soul of our pueblo."

The court left for later the decision about where the condemned men will complete their sentences. For now, Bussi will continue under house arrest, a decision that provoked dozens of demonstrators outside the courthouse to pelt police clad in riot gear with rocks.

"I'm satisfied, but with sorrow in my heart," said Marta Cardenas, Vargas' widow. "I am convinced they were responsible. The only thing I lament is that they didn't have a little pity on us to tell us what really happened, what they did with Guillermo, where he is. That causes us much sadness. ... There is always that sensation that we're missing something."

Cardenas rejected the actions of the demonstrators.

"I don't believe in violence as a mechanism to impose anything," she said.

Vargas' son, Guillermo Vargas Aignasse, said he was pleased with the decision.

"It's been a long wait," he told Canal 7. "I hope that all the families of victims who have not had a judgment will be able to identify with this. I hope the condemned live a long time."

As many as 30,000 people are estimated to have been killed during the Dirty War, from 1976 to 1983, when Jorge Rafael Videla's military government cracked down on dissidents.